docs: def dig(obj, *keys):
      """
      Return obj[key_1][key_2][...] for each key in keys, or None if any key
      in the chain is not found
  
      So, given this `obj`:
  
      {
          "banana": {
              "cream": "pie"
          }
      }
  
      dig(obj, "banana") -> {"cream": "pie"}
      dig(obj, "banana", "cream") -> "pie"
      dig(obj, "banana", "rama") -> None
      dig(obj, "Led", "Zeppelin") -> None
      """
      for key in keys:
          if not obj or key not in obj:
              return None
          obj = obj[key]
      return obj